Method for navigation of a vehicle

ABSTRACT

Method for navigating a vehicle in a road system is provided, in which method data is read from a data-storage medium and automatically transferred to a memory of a navigation device after the data medium is inserted into a data-media drive associated with the navigation device. The transferred data remains available for vehicle navigation even after the data medium is removed from the data-media drive.

FIELD OF THE INVENTION

The present invention is directed to a method for navigating a vehiclein a road system.

BACKGROUND INFORMATION

Navigation devices that require a data medium, e.g., a compact disc or aDVD (digital versatile disc), in order to perform navigation are alreadyknown. A digital map containing a road system is placed on the datamedium, the navigation device regularly accessing the data medium tocalculate the trip route and to output driving instructions. Theexpensive data-media drive is thus available in the vehicle only for thenavigation device, or the drive cannot be used for other data mediawhile vehicle navigation is being carried out. Navigation methods inwhich a navigation device in the vehicle accesses an external databasewithout requiring a data medium in the vehicle are also known. However,additional costs are thereby incurred for data transfer.

SUMMARY

The method according to the present invention for navigating a vehiclein a road system has the advantage over the related art in thatnavigation data is automatically transferred to a memory of thenavigation device immediately after the data medium is inserted into adata media drive. The transferred data is then available to thenavigation device for vehicle navigation purposes, i.e., in particularfor calculating the trip route and outputting driving instructions aswell as for outputting additional information, without having to accessthe data medium again. As a result, the data-media drive may also beused for other purposes, e.g., for playing music or video data. Inaddition, navigation is possible within a limited area even withoutinserting a data medium, if permitted by the storage capacity of thenavigation device memory. The direct access to the memory assigned tothe navigation device also shortens the navigation-data access time.

It is advantageous that the inserted data medium may be removed afterthe navigation data has been transferred and another data medium may beinserted without having to interrupt the navigation function. This makesit possible, in particular, to link the data of different data media inthe navigation device, e.g., the data media of different manufacturersor data media having different content. One example of this is linking afirst data medium containing map data with a second data mediumcontaining tourist information that may then be evaluated together bythe navigation device.

A further advantage of the present invention is that a first map area isstored on a first data medium and a second map area on a second datamedium, so that the trip route may be planned from the first map area tothe second map area. For example, if a trip is to cross the border fromGermany to France, the Germany CD may be inserted first and its relevantdata transferred to the memory. A CD containing French map data is theninserted, the route also being planned through France. It is no longernecessary to subsequently change data media, since the relevantnavigation data has been automatically transferred to the memory of thenavigation device without prompting the user. The stored data may alsobe combined from multiple data sources, e.g., a travel guide for a mixedtour compiled from different travel guide data media, or navigation datacombined from data media for multiple areas.

A further advantage of the present invention is that audio and/or videodata may be stored on a second data medium, so that, for example,navigation does not have to be interrupted to play music, nor does anadditional drive need to be installed in the vehicle, for example for amusic compact disc.

It is further advantageous to store the data transferred from the datamedium through non-volatile means in the navigation device so that thedata remains available for further vehicle navigation even after turningoff the vehicle or after a power failure.

It is further advantageous to store the data dependent on a selectedfunction, the planned route or the present vehicle position. Forexample, the data that is especially likely to be accessed istransferred from the data medium to the navigation device.

In this regard, it is particularly advantageous to store data for thearea surrounding a trip route so that it is not necessary to access thedata medium again when traveling along the trip route within a corridorof a preselected width.

It is further advantageous to convert the navigation data to a differentdata format during the transfer. In particular, if the data is stored onthe data medium in coded form, this makes it possible to store uncodeddata directly in the memory assigned to the navigation device. This alsomakes it possible to convert data media of different manufacturersdirectly to a data format that is compatible with the navigation devicewhen transferring data to the navigation device memory, so that theconversion of the data format does not take up any extra time whenaccessing the corresponding data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a navigation device according to thepresent invention for carrying out the method according to the presentinvention.

FIG. 2 shows a flowchart of a portion of an exemplary embodiment of themethod according to the present invention.

FIG. 3 shows a flowchart of another portion of the exemplary embodimentof the method according to the present invention.

DETAILED DESCRIPTION

FIG. 1 shows a navigation device 1 that is connected to a display unit2. Navigation device 1 has an arithmetic unit 3, a main memory 4, amemory 5 for navigation data and a playback device 6 for audio and/orvideo data. In addition, a loudspeaker 7 is connected to navigationdevice 1, the loudspeaker of the car radio. Display unit 2 has a displayarea 8, which may be designed as a liquid crystal display. A maprepresentation 9 having a road representation is displayed in displayarea 8. In addition, a control menu 10 that is operated by controls 11next to display area 8, and which is used to control navigation device1, is displayed in display area 8. A positioning device 12, which may bea GPS (Global Positioning System) satellite positioning device, may beused to determine a position of the vehicle in which navigation device 1is located, via contact with a satellite 13. Additional data isretrievable from a mobile communications network 16 via a radiointerface 14. In particular, a connection to the Internet is possible. Adata media drive 15 into which a data medium 20 is insertable is alsoconnected to navigation device 1. Data medium 20 may be ejected at theuser's request and replaced by a second data medium 21. In a furtherexemplary embodiment, the data media drive may also be integrated intonavigation device 1, or a data medium, e.g., a memory card, may insteadbe connected directly to navigation device 1 via a suitable interface.

Data media 20, 21 may be magnetic and/or optical data media, e.g., inthe form of a compact disc, a magneto-optical disc or a DVD (digitalversatile disc). Playback device 6 is used, in particular, as an audioor video tuner, a video signal being output via display unit 2 and anaudio signal being output via loudspeaker 7. Main memory 4 is designedas a volatile memory and assigned to arithmetic unit 3. Memory 5 is usedto record the navigation data transferred from data medium 20 tonavigation device 1. In an exemplary embodiment, memory 5 is designed asa non-volatile memory, e.g., as a battery-backed volatile memory such asa RAM (random-access memory), a hard disk, a memory card or a rewritablemagnetic and/or optical data medium. When data medium 20 is insertedinto data media drive 15, arithmetic unit 3 initiates an automatictransfer of navigation data to memory 5. The navigation data is, forexample, data of a digital road map. Further navigation data includes,for example, additional information such as information on road traffic,hotels and restaurants, tourist sights or gas stations as well as restareas. Up-to-date traffic information is also retrievable via airinterface 14 and taken into account for vehicle navigation. After theuser makes an entry via controls 11, navigation device 1 calculates atrip route from the vehicle position determined via positioning device12 to a destination entered via controls 11 on the basis of thenavigation data transferred to memory 5. Arithmetic unit 3 uses thisinformation to determine driving instructions, which are output to thedriver via the loudspeaker and/or display unit 2.

In an exemplary embodiment of the method according to the presentinvention, data is input from different navigation data media and takeninto account for vehicle navigation. If a user would like to drive, forexample, from a city in Germany to a French city, and if the road mapinformation is only located on two different data media, the user isfirst prompted to insert the first data medium containing the German mapdata. A portion of the map data is transferred to memory 5, depending onthe present vehicle position. The user is then prompted to insert thesecond data medium containing the French map data. The optimum triproute is determined on the basis of the transferred map data. If theuser removes the data medium from data media drive 15 too early, awarning thereof is output via the loudspeaker and/or display 2.

FIG. 2 shows a flowchart of a portion of an exemplary embodiment of amethod according to the present invention. Based on a prompt step 30, auser is prompted to insert a navigation data medium into data mediadrive 15. In a determination step 31, the data transferred to memory 5of navigation device 1 is then determined, for example, as a function ofthe trip route or the destination entered via controls 11. In asubsequent transfer step 32, this data is read from data medium 20immediately, if possible, after data medium 20 is inserted, transferredto navigation device 1 and stored in memory 5. There, the data isavailable for processing by arithmetic unit 3. It is not necessary toprompt the user to transfer the data, since the data transfer is startedautomatically by navigation device 1. A further transfer desired by theuser may also be requested, for example, via control panel 11. Ifnecessary, the data is decoded by arithmetic unit 3 during the transfer.In a subsequent notification step 33, a message to the user is outputstating that the necessary data transfer has been completed and the datamedium is no longer needed for the time being. If the user would like toplay music or a video, he may insert another data medium 21 into datamedia drive 15 and start playing music 34. In a subsequent checking step35, a check is carried out at regular, preselected intervals toascertain whether the data medium is needed again. While traveling thepreviously calculated route, this will not be the case, since allrelevant data is stored in memory 5 and thus available to arithmeticunit 3. If data medium 20 is not needed, music playback 34 continues.If, however, it is determined that the previous data medium is requiredagain, or that another data medium must be inserted, the method branchesback to prompt step 30.

FIG. 3 shows another portion of the exemplary embodiment of a methodaccording to the present invention. Based on a route calculation step40, a trip route is calculated from a starting point to a destination,if necessary, including necessary driving instructions. In a subsequentdetermination step 41, the navigation data transferred from data medium20 to memory 5 is determined. In particular, a corridor surrounding thetrip route is determined. This corridor may be determined, for examplenarrowly in the vicinity of the starting point and destination, thenbroadened as needed in the direction of the middle of the route. Ifnecessary, it is also possible to make an assignment to geographicsectors that are limited, for example, by specifying limits in acoordinate system, e.g., the degrees of longitude and latitude. Ifnecessary, driver preferences that may be stored in, or arepreselectable by, navigation device 1 may be taken into account. Forexample, only side streets, or only the data of highways, may betransferred. This transfer then takes place in subsequent transfer step42. In a subsequent output step 43, the individual driving instructionsand any necessary additional tourist information are optically and/oracoustically output to the user via display unit 2 and/or loudspeaker 7.In a subsequent position checking step 44, the present vehicle positionis checked. If it is determined that the destination has been reached,the vehicle navigation ends in a termination step 45. If it isdetermined that the vehicle is still located in the predefined corridor,the method branches back to output step 43 for outputting the next setof driving instructions. If it is determined in position checking step44 that the vehicle has left the corridor, for example due to a trafficholdup, either at the user's request or due to a necessary route changeas a result of a traffic holdup transmitted via air interface 14, themethod branches back to route calculation step 40, and the trip route ismodified. Although the data medium is no longer needed followingtransfer step 42, it must nevertheless be inserted again for routecalculation step 40.

It is also possible to display, in display area 8, the time remaininguntil the data has been fully transferred to memory 5. In particular,the prompt to insert the data medium may also be output acoustically vialoudspeaker 7. Likewise, a warning is output if the data has not yetbeen fully transferred to memory 5.

1. A method for performing a vehicle navigation along a road systemusing a navigation device, comprising: receiving a destination inputfrom a user of the navigation device; prompting the user to insert afirst data medium containing navigation data, including a first map areacorresponding to a starting location of a vehicle, into a data-readingarrangement associated with the navigation device, wherein thedata-reading arrangement is a data-media drive connected to thenavigation device; automatically transferring the navigation data to amemory of the navigation device; after automatically transferring thenavigation data to the memory, determining, at the navigation device,that the first data medium does not contain navigation data needed toreach the destination; responsive to the determining, prompting the userto replace the first data medium with a second data medium containingthe needed navigation data, including a second map area corresponding tothe destination, wherein the second data medium does not contain datacorresponding to the first map area; after the first data medium isreplaced with the second data medium, automatically transferringadditional navigation data from the second data medium to the memory; atthe navigation device, responsive to the transferring of the additionalnavigation data, calculating a trip route from the first map area to thesecond map area, using the automatically transferred navigation data tocalculate a portion of the trip route along the first map area, andusing the additional navigation data to calculate a portion of the triproute along the second map area; and outputting navigation instructionsto the user based on the calculated trip route.
 2. The method as recitedin claim 1, wherein selective portions of the navigation datacorresponding to map features along the trip route are stored in thememory as a function of at least one of: a selected function of thenavigation device; a user profile; a present vehicle position; and acalculated trip route.
 3. The method as recited in claim 2, wherein datafor a selected area surrounding the calculated trip route is stored inthe navigation device.
 4. The method as recited in claim 1, furthercomprising: changing a data format of the navigation data during theautomatic transfer of the navigation data to the memory.
 5. The methodas recited in claim 1, further comprising: changing a data format of thenavigation data during the automatic transfer of the navigation data tothe memory; wherein selective portions of the navigation datacorresponding to map features along the trip route are stored in thememory as a function of at least one of: a selected function of thenavigation device, a user profile, a present vehicle position, and acalculated trip route, and wherein data for a selected area surroundingthe calculated trip route is stored in the navigation device.
 6. Themethod as recited in claim 3, wherein a width of the surrounding area isnarrower in the vicinity of the starting location and the destinationcompared to a width of the surrounding area near the middle of thecalculated trip route.
 7. The method as recited in claim 1, furthercomprising: changing a data format of the navigation data during theautomatic transfer of the navigation data to the memory; whereinselective portions of the navigation data corresponding to map featuresalong the trip route are stored in the memory as a function of at leastone of: a selected function of the navigation device, a user profile, apresent vehicle position, and a calculated trip route, and wherein datafor a selected area surrounding the calculated trip route is stored inthe navigation device, and wherein a width of the surrounding area isnarrower in the vicinity of the starting location and the destinationcompared to a width of the surrounding area near the middle of thecalculated trip route.
 8. The method as recited in claim 7, whereinselective portions of the navigation data corresponding to map featuresalong the trip route are stored in the memory as a function of at leastone of: a selected function of the navigation device; a user profile; apresent vehicle position; and a calculated trip route, and wherein datafor a selected area surrounding the calculated trip route is stored inthe navigation device.
 9. A method for performing a vehicle navigationalong a road system using a navigation device, comprising: transferringnavigation data contained in a first data medium to a memory of thenavigation device; calculating a trip route using the transferrednavigation data; after calculating the trip route, locating, in thefirst data medium, additional navigation data corresponding to an areasurrounding the trip route, wherein the navigation device determines thearea surrounding the trip route narrowly in a vicinity of a startingpoint and a destination, relative to a portion of the area surroundingthe trip route corresponding to a middle of the route; transferring theadditional navigation data from the first data medium to the memory;outputting navigation instructions based on the calculated trip route;periodically determining whether the vehicle is located in the areasurrounding the trip route; and responsive to determining that thevehicle is no longer in the area surrounding the trip route,re-calculating the trip route using new navigation data from the firstdata medium.